The opening of the book serves as a preamble to Coste's investigation into the realm of psychic phenomena, laying the groundwork for his arguments. He discusses the historical context that has affected the perception of the marvelous and the supernatural in human thought, emphasizing that many aspects once dismissed as superstition warrant serious scientific inquiry. Coste highlights the reluctance within the scientific community to engage with these mysterious phenomena, and he presents the arguments made by various scholars in favor of exploring what he terms "occult psychic phenomena." Ultimately, he expresses an intention to scientifically categorize and study these phenomena, suggesting an evolving understanding in a contemporary context that may allow for their acceptance within the realm of science. (This is an automatically generated summary.)